We next convert the two given fractions so that they have common denominator equal to the LCM = 18. The denominator of the fraction _{} is 9 and we need to multiply numerator and denominator by 2 in order to change the denominator to 18

The denominator of the fraction _{} is 6 and we need to multiply numerator and denominator by 3 in order to change the denominator to 18

Now that we have converted the two fractions so that they have common denominator, we can easily add them as follows

Example 4: Add, simplify and express the final answer as a fraction and as a mixed number.

Solution to Example 4

Find the LCM of the denominators 15 and 55

We convert the given fractions so the they have common denominator equal to the LCM = 165. The denominator of the fraction
_{} is 15 and both numerator and denominator need to be multiplied by 11 in order to change the denominator to 165

The second fraction _{} is converted to one with the denominator equal to 165 by multiplying numerator and denominator by 3 in order to change the denominator to 165

We now add the fractions

Example 5: Add, simplify and express the final answer as a fraction.

Solution to Example 5

We first convert 2 into a fraction

The common denominator will be 5

We now add

Exercises: Add, simplify and express the answer as a fraction and as a mixed number.